The use of explosive or otherwise dangerous devices by terrorists and criminals is an increasing threat. For example, the use of improvised explosive devices (IEDs) by terrorists continues to threaten both civilians and U.S. military personnel in Iraq. As of March 2008, approximately 1,650 U.S. casualties had been reported from IEDs, and a total number of 4,000 casualties had been reached in Iraq. Threats also exist in common portals such as airports, seaports, transit stations, and the like.
Current methods of detection fail to adequately and safely identify or disable IEDs and other dangerous materials. For example, signal jamming is currently an often used technology in Iraq. Signal jamming may effectively disable an IED in some cases. However, signal jamming attacks the user and not the device itself, and terrorists are adapting IEDs to avoid signal jamming techniques.
Other solutions including residual chemical analysis may be used to determine the presence or use of explosive materials. However, close contact is required with the target. Often such contact may be dangerous and undesired.
Another solution has been to use neutron or photon imaging techniques. Such techniques may require a significant amount of resources. This may include the necessity for devices that produce images with very high spatial resolution, along with the requirement that human operators be trained to interpret the images. Even with training, human operators are prone to making mistakes in identifying certain objects as threats.